The chapter introduces the principles of radar systems, focusing on pulsed radar. It covers the following key points: 1. **Principles of Radar**: - Radar uses reflected radio signals to detect and locate objects. - The speed of light is crucial for understanding radar operations. - Frequency bands are established by the International Telecommunications Union (ITU). 2. **Radar Wavelengths**: - Different wavelengths are used for various radar applications, such as primary approach radar (3cm to 10cm) and primary area radar (23cm to 50cm). - The choice of wavelength depends on the specific role of the radar system. 3. **Primary Surveillance Radar**: - Primary radar can be used for long-range tracking, airfield surveillance, surface movement radar, terminal weather radar, and more. - The process involves transmitting a microwave signal, receiving reflected signals, and processing them to extract information about the target. 4. **Mathematical Formulation of Pulsed Signals**: - Pulsed signals are short pulses with very high power. - The mathematical formulation of a train of pulses is provided, including the pulse repetition time (PRT), pulse repetition frequency (PRF), pulse width (τ), and operating frequency (f₀). 5. **Characteristics of Pulsed Signals**: - Modulation in frequency is necessary for transmission. - Key characteristics include PRT, PRF, τ, and f₀. 6. **Range Ambiguity and Minimum Range**: - Range ambiguity occurs due to the Doppler effect. - The minimum range (blind range) is determined by the pulse width and the speed of light. 7. **Range Resolution**: - Range resolution is crucial for distinguishing between closely spaced objects. - It is given by the formula \(\Delta R = \frac{c \cdot \tau}{2}\), where \(c\) is the speed of light and \(\tau\) is the pulse width. The chapter provides a comprehensive overview of the fundamental principles and technical aspects of pulsed radar systems.The chapter introduces the principles of radar systems, focusing on pulsed radar. It covers the following key points: 1. **Principles of Radar**: - Radar uses reflected radio signals to detect and locate objects. - The speed of light is crucial for understanding radar operations. - Frequency bands are established by the International Telecommunications Union (ITU). 2. **Radar Wavelengths**: - Different wavelengths are used for various radar applications, such as primary approach radar (3cm to 10cm) and primary area radar (23cm to 50cm). - The choice of wavelength depends on the specific role of the radar system. 3. **Primary Surveillance Radar**: - Primary radar can be used for long-range tracking, airfield surveillance, surface movement radar, terminal weather radar, and more. - The process involves transmitting a microwave signal, receiving reflected signals, and processing them to extract information about the target. 4. **Mathematical Formulation of Pulsed Signals**: - Pulsed signals are short pulses with very high power. - The mathematical formulation of a train of pulses is provided, including the pulse repetition time (PRT), pulse repetition frequency (PRF), pulse width (τ), and operating frequency (f₀). 5. **Characteristics of Pulsed Signals**: - Modulation in frequency is necessary for transmission. - Key characteristics include PRT, PRF, τ, and f₀. 6. **Range Ambiguity and Minimum Range**: - Range ambiguity occurs due to the Doppler effect. - The minimum range (blind range) is determined by the pulse width and the speed of light. 7. **Range Resolution**: - Range resolution is crucial for distinguishing between closely spaced objects. - It is given by the formula \(\Delta R = \frac{c \cdot \tau}{2}\), where \(c\) is the speed of light and \(\tau\) is the pulse width. The chapter provides a comprehensive overview of the fundamental principles and technical aspects of pulsed radar systems.